What it does
The developed technology is a compact, top-storey mounted device that reduces seismic vibrations without adding mass or requiring major structural modifications. It enables building owners to retrofit quickly, cost-effectively, and with minimal disruption.
Your inspiration
The idea arose from witnessing a recurring pattern, earthquakes causing the collapse of buildings and inevitably casualties. While several technologies exist to make structures resilient, most solutions are complex, expensive, or require large parts of the building to not be operational. This motivated us to develop a more practical solution, that is accessible, effective, and minimally intrusive. The inspiration of the developed NegSV technology stems from the field of metamaterials, formations that exhibit extraordinary properties. Similarly, the NegSV generates unique effects, ensuring buildings are protected, while minimally compromised.
How it works
The NegSV reduces earthquake vibrations by adjusting a building’s dynamic behavior. It’s installed at or near the top floor, where it lowers horizontal stiffness using an innovative arrangement of prestressed springs and cables. It creates the counterintuitive effect of negative stiffness, while keeping vertical support intact. This makes the top floor act like a resonator, absorbing and redirecting energy away from the building’s main structural elements. In other words, it appropriately adapts the existing building so that it protects itself. Therefore, this technology does not require the addition of extra mass, while it operates efficiently across a variety of earthquake characteristics. Energy is safely dissipated within the device itself, thus protecting the structure from damage.
Design process
The development of the NegSV involved several steps, while the quest of such system initiated within a separate field that transitioned to the current technology, after some compelling observations. The design process began with the study of metamaterials and a respective experimental investigation, which inspired the concept of using negative stiffness for vibration control. This foundational research in combination with smart tuning of structural dynamics demonstrated the potential to reduce damage. Building on these insights, Kyriakos Chondrogiannis, during his PhD, conceptualized and developed the NegSV system. He transformed the theoretical metamaterial principles into a practical retrofitting device suited for real-world buildings. Meticulous engineering design and modeling resulted to a scaled prototype, which was experimentally validated, revealing remarkable performance. The design further advanced through numerical modeling, optimization, and full-scale adaptation for reinforced concrete frames. Integration into real structures is currently under development via physical testing at ETH Zurich. This innovation combines metamaterial principles with practical retrofitting needs, designed for deployment in the seismic retrofitting market.
How it is different
The NegSV device is a new type of seismic retrofitting solution that stands out for its simplicity, light weight, and minimal disruption. Unlike traditional systems, as for example tuned mass dampers or base isolation, it does not rely on added mass or significant structural changes. Instead, it uses negative stiffness at the top of the building to reduce vibrations directly, turning part of the structure itself into an energy dissipation system. This makes it very convenient and cost-efficient to install, especially in older buildings that can not support heavy equipment or foundation-level work. Notably, the NegSV also preserves the building’s architectural and operational integrity, something that is often lacking with current retrofitting methods. The NegSV bridges the gap between lab innovation and real-world application by offering a practical solution that can be adapted to a wide range of existing buildings.
Future plans
Builtstop is currently finalizing the full-scale design of the NegSV device and validating it through real-world testing. We are building a minimum viable product that meets both technical and market needs. On the business side, we are preparing a commercialization strategy with pricing, licensing, and partnerships, and we plan to file for patent protection. Over the next year, we aim to secure industry partnerships and pilot projects. Long-term, we want to scale in seismic-prone regions like Italy, Greece, and Turkey, while further plans include global expansion.
Awards
The project was awarded the ETH Pioneer Fellowship and has won the Startup Campus Award. Builtstop is further supported by the Innosuisse initial coaching grant and the Runway incubator, while we are part of the Swiss sustainability challenge. These achievements reflect on the technical novelty and the business viability.
Connect